A Most-Wanted Cyberthief Is Caught in His Own Web

After a search of more than two years, a team of F.B.I. agents early this morning captured a 31-year-old computer expert accused of a long crime spree that includes the theft of thousands of data files and at least 20,000 credit card numbers from computer systems around the nation.

The arrest of Kevin D. Mitnick, one of the most wanted computer criminals, followed a 24-hour stakeout of an apartment building here.

A convicted computer felon on the run from Federal law enforcement officials since November 1992, Mr. Mitnick has used his sophisticated skills over the years to worm his way into many of the nation's telephone and cellular telephone networks and vandalize government, corporate and university computer systems. Most recently, he had become a suspect in a rash of break-ins on the global Internet computer network.

"He was arguably the most wanted computer hacker in the world," said Kent Walker, an assistant United States attorney in San Francisco who helped run the investigation. "He allegedly had access to corporate trade secrets worth millions of dollars. He was a very big threat."

But Federal officials say Mr. Mitnick's confidence in his hacking skills may have been his undoing. On Christmas Day, he broke into the home computer of a computer security expert, Tsutomu Shimomura, a researcher at the federally financed San Diego Supercomputer Center.

Mr. Shimomura then made a crusade of tracking down the intruder, a pursuit that led to today's arrest. [ Page D17. ]

Mr. Shimomura, working from a monitoring post in San Jose, Calif., determined last Saturday that Mr. Mitnick was operating through a computer modem connected to a cellular telephone somewhere near Raleigh, N.C.

Mr. Shimomura was present today at Mr. Mitnick's prearraignment hearing at the Federal courthouse here. At the end of the hearing, Mr. Mitnick, who now has shoulder-length brown hair and was wearing a black sweat suit and handcuffs, turned to Mr. Shimomura, whom he had never met face to face.

"Hello, Tsutomu," Mr. Mitnick said. "I respect your skills."

Mr. Shimomura, who is 30 and also has shoulder-length hair, nodded solemnly.

Mr. Shimomura had flown on Sunday morning to Raleigh, where he helped telephone company technicians and Federal investigators use cellular-frequency scanners to home in on Mr. Mitnick.